Two things jumped out at me. First, no Mana Echoes with Spawnsire of Ulamog? Second, they can just sacrifice the Eldrazi to its own Annihilator ability when you use Evil Presents.

RE: Evil Presents, thats what I was about to say. At least you get to do it in the first few turns if nothing else. But if you are trying to abuse the presents, then having a Dark Ritual would help, attacking themselves with a Em, and sacrificing all permanents on turn 3 or so is a game winner...

98% of people use statistics in their sigs, or have used them in the past. If you are one of the 2% that haven't or don't, place this into your signature.
New Magic Forums, Im'a let you finish, but the old Magic Forums were one of the greatest boards of all time!

If I got it right, Essence Warden helps you get infinite life. You get infinite mana with 2 Training Grounds and a Spawnsire. You pay 1 to to get 2 tokens, which you can sacrifice to get 2 more spawn tokens from each one sacrificed.

Essence Warden lets you gain infinte life with just availible. You pay , get 4 tokens (gain 4 life). Sac those 4 tokens for , and repeat the cycle. You could replace Essence Warden with any EtB or Sac or graveyard trigger that you want. But, Doubling Season basicly makes this Elddrazi an endless machine.

Evil Presents: Since your opponent controls the Eldrazi, they will just sacrifice it to the first Annihilator trigger. No big deal, since you only payed 4 mana for it. But, if you use one of the smaller ones, they will sac it plus 1 or 2 more permanents only. You'd really want the bigger ones, Annihilator 4 or Annihilator 6 to make it really game over.

And on a more serious note:

Conspiracy + Spawnsire of Ulamog! Turn every card you own outside the game into an Eldrazi. Then, pay and play EVERYTHING YOU OWN for free. EVERYTHING! Mwahahahahahahahahahahahahahahahahaha *coughing fit*

Obviously Essence Warden lets you gain infinite life. Jakusotsu is pointing out a little mistake in the article: "If you have an effect such as Essence Warden, you can rinse and repeat for infinite mana."